<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const age = Symbol("age");
      const user = {
        [age]: 20,
        [Symbol("name")]: "jack",
      };
      console.log(user.name, user.age);
      console.log(user[age]);
    </script>
  </body>
</html>
